Product dispensers of the type under consideration in this application are well known. With reference to FIG. 1, a particular wall-mounted type dispenser is shown and designated by the numeral 10. The dispenser 10 includes a housing 12 comprised of a back plate 13 and a cover 14. The back plate 13 is typically mounted to a wall, and the cover 14 is pivotally secured thereto, as at hinge 16, so that it can pivot relative to the back plate 13 from a closed position, as shown in FIG. 1, to an open position (not shown, but well known) so that the dispenser housing 12 can accept a refill unit of product.
As seen in FIG. 2, the refill unit 20 includes a product container 22 holding a volume of product P for dispensing. A pump 24 is secured to the container 22, and communicates with the interior thereof, such that, upon actuation of the pump 24, product P is advanced to the outlet 26 of the pump 24. As seen in FIG. 1, the outlet 26 is positioned so as to dispense to a user's hand. Actuation of the pump 24 may be initiated by a touchless sensor 28 sensing the presence of the hand below the outlet 26.
Some dispensers employ pumps that advance and dispense continuously, with the volume thus dispensed being dictated by the amount of time that the pump is actuated. These pumps can be considered to have variable dispense cycles in that the dose of product they provide varies with the duration of the continuous actuation of the pump. Gear pumps and impeller pumps are good examples of such pumps. Other dispensers employ pumps that have discrete dispense cycles, wherein only a unit dose of product is dispensed upon actuation of the pump. These pumps typically operate by trapping a fixed amount (i.e., discrete dose) of product and then displacing that fixed amount to a discharge area. Peristaltic pumps, dome pumps, and reciprocating piston pumps are good examples of pumps that dispense through such a discrete dispense cycle. Pumps having discrete dispense cycles are the focus of this invention.
A pump has a “discrete dispense cycle” when the pump has an actuated state and an unactuated state, with the pump dispensing a discrete dose of product upon manipulation from the unactuated state to the actuated state. At some point during the dispense cycle, the pump is recharged with another discrete dose of product. In certain pumps having discrete dispense cycles, the pump is recharged with another dose of product upon return from the actuated state to the unactuated state, and, in other pumps having discrete dispense cycles, the pump is recharged with another dose of product at the start of the actuation of the next dispense cycle. Broadly, a “discrete dispense cycle” is to be understood as the cycle through which the pump progresses to dispense a single discrete dose. Typically this will involve manipulating the pump from the unactuated state to the actuated state to dispense product, followed by the return of the pump from the actuated state to the unactuated state, but this invention is not necessarily limited to or by such pumps. The “discrete dose” of product is simply the volume of product dispensed upon one actuation of the pump, or upon one progression through the discrete dispense cycle.
In the dispensers of the prior art that employ pumps having discrete dispense cycles, the pumps are designed with the intention that a single actuation of the pump, i.e., manipulation through a single discrete dispense cycle, is to provide an adequate dose of product suitable for the end use of that product. For example, in the case of soap dispensers, one actuation of the pump is intended to provide an adequate dose of soap for washing one's hands. In the art of soap dispensing and in personal care product dispensing in general, this has been the practice for decades.
Because a single actuation of the pump is to provide a suitable dose of product, to the extent that different applications require different doses of product, the pump must be specifically designed for each application. For example, in an application where a 2 ml dose of product is desired, the pump will have to be designed so that it dispenses 2 ml of product upon a single actuation, and, in an application where a 1 ml dose is desired, the pump will have to be designed so that it dispenses 1 ml of product upon a single actuation.
For those business entities that design, manufacture and/or supply dispensers employing pumps having discrete dispense cycles, it is inefficient to have to design, manufacture and supply different pumps for different applications requiring different doses of product. Additionally, when operating a dispenser having a pump with a discrete dispense cycle, the only way to dispense a dose of product different from the discrete dose is to require the user to actuate the pump multiple times or to “short stroke” the pump or perform some combination of full actuation and short stroking. Pumps with discrete dispense cycles are “short stroked” when the pump is not fully actuated and therefore only dispenses a portion of the intended discrete dose. Short stroking often has negative effects on subsequent actuations of the pump.
It should also be appreciated that it takes a certain amount of power to manipulate a pump through a discrete dispense cycle. For battery powered dispensers employing pumps with discrete dispense cycles, the dispenser will cease to operate once the power supplied by the battery is lower than the power needed to manipulate the pump to the actuated state.
It should also be appreciated that the physical size of the pump varies depending on the dose it is designed to dispense. In general, the size of the discrete dispense cycle pump is proportional to the size of the dose it dispenses, such that the larger dose a discrete dispense cycle pump is designed to dispense, the larger the physical size of the pump. For example, a pump designed to dispense 2 ml in a single dose is typically (if not axiomatically) larger than a pump designed to dispense a 1 ml dose of product.
In light of the forgoing, dispensers employing pumps with discrete dispense cycles could be improved by designing the dispensers such that they can be made to dispense differing desired doses of product without requiring different pumps. The art could be further improved by providing battery-powered dispensers that more efficiently utilize the power in the batteries.